Webengine compilation error during qt5.git integration in '5.10'

FAILED: obj/cc/paint/paint/paint_op_buffer.o 
/usr/bin/g++ -MMD -MF obj/cc/paint/paint/paint_op_buffer.o.d -DCC_PAINT_IMPLEMENTATION=1 -DV8_DEPRECATION_WARNINGS -DUSE_UDEV -DUSE_AURA=1 -DUSE_NSS_CERTS=1 -DUSE_X11=1 -DNO_TCMALLOC -DDISABLE_NACL -DFULL_SAFE_BROWSING -DSAFE_BROWSING_CSD -DSAFE_BROWSING_DB_LOCAL -DCHROMIUM_BUILD -DFIELDTRIAL_TESTING_ENABLED -DTOOLKIT_QT -D_FILE_OFFSET_BITS=64 -D_LARGEFILE_SOURCE -D_LARGEFILE64_SOURCE -D__STDC_CONSTANT_MACROS -D__STDC_FORMAT_MACROS -D_DEBUG -DDYNAMIC_ANNOTATIONS_ENABLED=1 -DWTF_USE_DYNAMIC_ANNOTATIONS=1 -D_GLIBCXX_DEBUG=1 -DSK_IGNORE_LINEONLY_AA_CONVEX_PATH_OPTS -DSK_HAS_PNG_LIBRARY -DSK_HAS_WEBP_LIBRARY -DSK_HAS_JPEG_LIBRARY -DSK_SUPPORT_GPU=1 -Igen -I../../3rdparty/chromium -I../../3rdparty/chromium/third_party/libwebp/src -I../../3rdparty/chromium/skia/config -I../../3rdparty/chromium/skia/ext -I../../3rdparty/chromium/third_party/skia/include/c -I../../3rdparty/chromium/third_party/skia/include/config -I../../3rdparty/chromium/third_party/skia/include/core -I../../3rdparty/chromium/third_party/skia/include/effects -I../../3rdparty/chromium/third_party/skia/include/encode -I../../3rdparty/chromium/third_party/skia/include/images -I../../3rdparty/chromium/third_party/skia/include/lazy -I../../3rdparty/chromium/third_party/skia/include/pathops -I../../3rdparty/chromium/third_party/skia/include/pdf -I../../3rdparty/chromium/third_party/skia/include/pipe -I../../3rdparty/chromium/third_party/skia/include/ports -I../../3rdparty/chromium/third_party/skia/include/utils -I../../3rdparty/chromium/third_party/skia/third_party/vulkan -I../../3rdparty/chromium/third_party/skia/include/gpu -I../../3rdparty/chromium/third_party/skia/src/gpu -I../../3rdparty/chromium/third_party/skia/src/sksl -fno-strict-aliasing --param=ssp-buffer-size=4 -fstack-protector -Wno-builtin-macro-redefined -D__DATE__= -D__TIME__= -D__TIMESTAMP__= -funwind-tables -fPIC -pipe -pthread -m64 -Wall -Wno-unused-local-typedefs -Wno-maybe-uninitialized -Wno-missing-field-initializers -Wno-unused-parameter -O0 -fno-omit-frame-pointer -g2 -fvisibility=hidden -std=gnu++11 -Wno-narrowing -fno-rtti -fno-exceptions -fvisibility-inlines-hidden -c ../../3rdparty/chromium/cc/paint/paint_op_buffer.cc -o obj/cc/paint/paint/paint_op_buffer.o
../../3rdparty/chromium/cc/paint/paint_op_buffer.cc:210:23: error: redeclaration ‘cc::PaintOp::kMaxSkip’ differs in ‘constexpr’
 const size_t PaintOp::kMaxSkip;
                       ^
In file included from ../../3rdparty/chromium/cc/paint/paint_op_buffer.cc:5:0:
../../3rdparty/chromium/cc/paint/paint_op_buffer.h:152:27: error: from previous declaration ‘cc::PaintOp::kMaxSkip’
   static constexpr size_t kMaxSkip = static_cast<size_t>(1 << 24);
                           ^
../../3rdparty/chromium/cc/paint/paint_op_buffer.cc:210:23: error: declaration of ‘constexpr const size_t cc::PaintOp::kMaxSkip’ outside of class is not definition [-fpermissive]
 const size_t PaintOp::kMaxSkip;
                       ^
[10984/21850] CXX obj/cc/paint/paint/paint_recorder.o